routine chem urinalysis and A&P Flashcards
hematuria
trauma to kidney
hemoglobinuria
presence of free hemoglobin in urine
interferences for blood
false negative: ascorbic acid
false positive: oxidants like bleach
acidic urine
prevents formation of alkaline kidney stones
inhibits development of UTIS
alkaline urine
prevents the precipitation and enhances the excretion of drugs
prevents the formation of acidic kidney stones
what are the 2 sources of protein in urine
plasma and RTE cells
protein interferences
false negative: presence of proteins that are not albumin
false positive: highly alkaline urines due to improper storage
clinical significance for nitrite
rapid screening for UTI
also can detect initial bladder infection (cystitis)
nitrite interferences
false negative: infection caused by pathogen that doesn’t reduce nitrate, ascorbic acid, insufficient incubation, absence of nitrate
false positive: contaminated specimen that has been sitting at room temp
reagent strip automation:
reflectance photometry
amount of reflected light indicate colour intensity
quantitative result
reagent strip QC for internal QC
performed daily & when new bottle is opened
reagent strip QC for external QC
proficiency survey
glucosuria is caused by?
hyperglycemia
what level of glucose is detected
2.2mmol/L
glucose interferences
false negative: ascorbic acid, improper storage
false positive: oxidizing agents like bleach
bilirubin
yellowish substance made during the bodies process of breaking down RBCs and helps diagnose liver disease
does normal urine contain bilirubin?
no
bilirubin interferences
false negative: ascorbic acids, nitrites, and improper storage
false positive: medications that induce colour in urine
bilirubin medications
phenazopyridine (UTIs)
indican
lodine (arthritis)
urobilinogen
only a small amount in normal urine
99% is eliminated in the feces (what gives it its colour)
urobilinogen interferences
false negative: nitrites, formalin, urine not at room temp or fresh
false positive: some drugs and atypical coloured urines
urobilinigen > oxidized > urobilin (yellow) =?
doesn’t react to test
conjugated bilirubin> oxidized > biliverdin (green) =?
does not react in tests
conjugated bilirubin >hydrolyzed > unconjugated bilirubin =?
insoluble and less reactive